Thickness is one characteristic of a membrane, not a complete measure of installed roof performance. Attachment, substrate, seams, flashings, and workmanship remain important. Comparing proposals by thickness alone can overlook larger scope differences.
What to do next
Ask for the complete assembly and installation documentation. Compare perimeter, penetration, and drainage work alongside the membrane selection. Keep product ratings separate from assumptions about the finished building's performance or expected service life.
Related Perkins guidance
Contact Perkins Roofing to discuss your roof and the appropriate next step.